JP2021116153A - Supporting platform for tower crane and climbing method using the same - Google Patents

Abstract

To provide a supporting platform for a tower crane capable of improving working efficiency for climbing and of reducing cost.SOLUTION: A supporting platform for a tower crane supports a horizontal load and a vertical load subjected to a lifting device to raise/lower a mast by taking a reaction force on the crane body of the tower crane. The supporting platform for the tower crane comprises an upper supporting part 11 detachably supported on a mast, a lower supporting part 12 detachably supported in a frame opening on the prescribed floor of a building, and a plurality of supporting legs 13 connected to the upper supporting part 11 and to the lower supporting part 12 by pin joints and arranged in a truss. The supporting legs 13 are provided in which the lower end is installed in an openable/closable state using the upper supporting part 11 as a fulcrum, when the lower supporting part 12 is not supported in the frame opening.SELECTED DRAWING: Figure 2

Description

The present invention relates to a support gantry for a tower crane and a climbing method using the same.

Conventionally, as a climbing method for a tower crane, the load of the crane body is supported by a temporary beam installed on the girder of the skeleton on a predetermined floor, and the crane base is pulled up to the girder of the skeleton on the upper floor from the support floor supporting the crane body. The method of landing on the floor is common (see, for example, Patent Document 1).

Another known climbing method is to use a support gantry. A climbing method using such a support gantry is a climbing method in which a support gantry for raising is mounted on a crane main body and the crane base is landed on the same floor as the support floor of the crane main body.

Japanese Unexamined Patent Publication No. 2000-327265

However, the conventional tower crane climbing method has the following problems.
That is, in the case of a general climbing method, a bad hole remains on the support floor on which the crane body is supported and the landing floor of the crane base on the upper floor, so it is necessary to take measures in case of rainfall. In addition, there is a risk that the finishing work process will be delayed due to the labor required for post-construction of the skeleton. Further, since the temporary beam replacement work is required for each climbing, it takes time and effort.
In addition, it is necessary to reinforce the skeleton on each of the support floor of the crane body and the landing floor of the crane base, which causes a problem that work efficiency is lowered.

In the case of the climbing method using the gantry as described in Patent Document 1 described above, since the skeleton shape and the crane model are different for each site, it is necessary to design the gantry according to the conditions of the site, which is troublesome. There was a problem that it cost money.
In particular, if the gantry is designed under conditions where the reaction force is supported by a large crane or the span is large, the design weight becomes large and it cannot be mounted on the crane body. In addition, when climbing without mounting the gantry on the crane body, it is necessary to replace and install the gantry for each climb, which takes time and effort, and there is room for improvement in that respect. ..

The present invention has been made in view of the above-mentioned problems, and provides a support gantry for a tower crane capable of improving work efficiency for climbing and reducing costs, and a climbing method using the same. The purpose.

In order to achieve the above object, the support frame for a tower crane according to the present invention is a tower crane that supports a horizontal load and a vertical load acting on an elevating device for raising and lowering a mast by taking a reaction force on the crane body of the tower crane. An upper support portion that is detachably supported by the mast, a lower support portion that is detachably supported by a skeleton opening on a predetermined floor of a building, the upper support portion, and the lower support portion. Of these, at least a plurality of support legs connected to the upper support portion by pin joining and arranged in a truss shape are provided, and the support legs are in a state in which the lower support portion is not supported with respect to the skeleton opening. The lower end portion is provided so as to be openable and closable with the upper support portion as a fulcrum.

Further, the climbing method using the tower crane support gantry according to the present invention is the climbing method using the tower crane support gantry described above, and the lower support portion of the tower crane support gantry is used as the skeleton opening. A step of supporting the mast and the horizontal load and a vertical load acting on the elevating device, a step of releasing the fixation of the mast to the skeleton of the building at the lower end of the mast, and raising the mast by the elevating device. The step of fixing the lower end to the raised floor skeleton opening, and the lower support portion is separated from the skeleton opening, and the plurality of support legs are contracted toward the mast center so as to be able to pass through the skeleton opening. It is characterized by having a step of closing the tower crane and a step of raising the support gantry for the tower crane together with the elevating device along the mast.

In the present invention, the support legs are vertically connected to the upper support portion by pin joining, and the lower end portion of the support legs has the upper support portion as a fulcrum when the lower support portion is not supported with respect to the skeleton opening. It is provided so that it can be opened and closed. Therefore, when climbing, the tower crane support gantry can be raised along the mast together with the elevating device by simply shrinking and closing multiple support legs toward the mast center so that they can pass through the skeleton opening. can. In particular, in the present invention, the support legs can be closed and climbing can be easily performed without interfering with the girder on the upper floor.
In this way, the crane body (elevating device) and the tower crane support gantry can be moved integrally, so it is like the case where the tower crane support gantry and the crane body are separate bodies as in the past. In addition, it is possible to reduce the time and effort required to relocate the support gantry separately from the crane body, and it is possible to improve the work efficiency of climbing.

Further, in the present invention, since the support legs have a structure that can be opened and closed with the upper support portion as a fulcrum, the position of the lower support portion provided at the lower part of the support legs is determined by the size of the skeleton opening, the installation span, and the like. It can be adjusted according to the conditions of. Therefore, it is possible to realize a tower crane support gantry with excellent versatility in installation, and it is not necessary to design and manufacture a tower crane support gantry according to the site, and the labor and cost required for design and manufacture. Can be reduced.

Further, in the present invention, since the support legs have a truss structure, the structure is strong against compression corresponding to the vertical load received from the crane body, so that the weight of the member can be reduced as compared with the conventional case, and the weight is reduced. Can be planned. Moreover, in the present invention, by making the support legs have a truss structure, it can be installed even on a girder having a large span forming a skeleton opening.
Further, in the present invention, since the support floor for the tower crane and the building frame is only one floor, the number of reinforcement points of the frame opening can be reduced and the number of climbs can be reduced. Therefore, it is possible to improve the efficiency of the refilling work.

Further, the support gantry for a tower crane according to the present invention is characterized in that the lower support portion is detachably supported between the plurality of support legs and is connected to a connecting frame forming the skeleton opening. May be good.

In this case, it is possible to realize a strong structure in which the lower support portion is connected to the connecting frame in which the skeleton opening is reinforced.

Further, the support gantry for a tower crane according to the present invention may be characterized in that the lower support portion is provided with a brace material that connects the plurality of support legs to each other and expands and contracts in the connecting direction.

In this case, the distance between the lower support portions can be adjusted by expanding and contracting the brace material. Therefore, the support gantry for the tower crane can be installed according to the installation span of the lower support portion.

According to the support gantry for a tower crane of the present invention and the climbing method using the support gantry, the work efficiency for climbing can be improved and the cost can be reduced.

It is a side view which shows the structure of the tower crane provided with the support frame by embodiment of this invention. It is a perspective view which shows the structure of the support structure shown in FIG. It is a figure which shows the open state before fixing a support frame to a skeleton girder, (a) is a perspective view, (b) is a side view. It is a figure which shows the closed state before fixing a support frame to a skeleton girder, (a) is a perspective view, (b) is a side view. (A) to (c) are diagrams showing an assembly procedure of a support gantry. (A) and (b) are diagrams showing the procedure for assembling the support gantry following FIG. 5 (c). It is a figure which shows the state which adjusted the dimension of the upper support part of the support gantry, (a) is the figure of the structure which does not insert the adjustment member in the upper support part, (b) is the figure which inserts the adjustment member in the upper support part. It is a diagram of the configuration. It is a figure which shows an example which installed the support gantry corresponding to the skeleton girder of a large span, and is the figure corresponding to FIG. 7B. It is a perspective view which shows the structure of the support structure by a modification.

Hereinafter, a support gantry for a tower crane according to an embodiment of the present invention and a climbing method using the support gantry will be described with reference to the drawings.

The tower crane support gantry (hereinafter, simply referred to as support gantry 1) according to the present embodiment shown in FIG. 1 is a tower crane installed inside the high-rise building (hereinafter, building 3) when it is installed or demolished. It supports the horizontal load and the vertical load acting on the lifting device 23 for raising and lowering the mast 22 by taking a reaction force on the crane body 21 of 2.
That is, the tower crane 2 supports the vertical load acting on the mast 22 (that is, the installation load acting downward in the vertical direction) and the horizontal load via the elevating device 23 by the support gantry 1 at a predetermined level while supporting the building 3 Floor climbing with the construction of.

Here, the skeleton opening of the building 3 in which the mast 22 is arranged is formed in a rectangular shape in a plan view by beams and floor slabs.

The tower crane 2 supports the crane main body 21 equipped with a lifting machine such as a jib and equipped with a driver's cab, the mast 22 arranged at the opening of the skeleton, and the crane main body 21 from below, and also with respect to the mast 22. It is provided with an elevating device 23 which is mounted so as to be able to elevate. A support gantry 1 supported by the skeleton girder 34 at the skeleton opening is fixed to the lower part of the elevating device 23.

The mast 22 has a rectangular columnar shape in a plan view, and is well known for extending its height by sequentially adding mast pieces of a predetermined length to the upper ends of the masts that have already been arranged. The lower end of the mast 22 is fixed to the skeleton girder 34 on a predetermined floor by a mast support pedestal 24 (see FIG. 6B). The mast 22 is provided with a crane main body 21, an elevating device 23, a support gantry 1, and a mast support pedestal 24 in this order from the upper part to the lower part. The mast support pedestal 24 is installed on the skeleton girder 34 on the predetermined floor of the building 3 or on the floor slab. The mast 22 is a self-supporting system by supporting the lower end. As described above, a part of the horizontal load and the vertical load of the crane main body 21 is supported by the skeleton of the building 3 via the mast 22, and the other part is supported by the skeleton of the building 3 via the support gantry 1.

At the lower part of the crane main body 21, a swivel device 211 for swiveling the crane main body 21 with respect to the upper surface of the elevating device 23 is provided. The swivel device 211 includes, for example, a gear that is rotated by a motor provided with a pinion (not shown), and the lower end portion of the crane body 21 that meshes with the gear is rotatably configured around the axis of the mast 22.

The elevating device 23 includes a lock pin mechanism (not shown), an elevating jack, and the like, and is arranged so as to surround the mast 22. The elevating device 23 includes a pair of upper and lower upper frames 231 and lower frames 232 that can be locked to the mast 22 by attaching and detaching a lock pin (not shown), and an elevating jack (not shown). The structure is such that the crane body 21 is climbed to the mast 22 by expanding and contracting the elevating jack while alternately fixing and opening the frame 232 to the mast 22 (FIGS. 6A and 6B). )reference).
Since the support gantry 1 is integrally provided at the lower part of the elevating device 23, it is configured to be able to ascend as the elevating device 23 rises.

As described above, in the present embodiment, the crane main body 21 is fixed to the skeleton of the building 3 by the elevating device 23, and in this state, the reaction force at the time of refilling the mast 22 can be taken, and the elevating device 23 can be moved. It has a structure that raises the mast 22 by driving it.

Next, a specific configuration of the support gantry 1 of the present embodiment will be described with reference to the drawings.
As shown in FIGS. 2 to 4, the support gantry 1 is fixed to the skeleton girder 34 of the building 3 shown in FIG. 1 when the mast 22 is raised by taking a reaction force against the crane body 21 (elevating device 23). It has a structure that makes it possible.
The support gantry 1 includes an upper support portion 11 that is detachably supported by the mast 22 via an elevating device 23, a lower support portion 12 that is detachably supported by a skeleton girder 34 on a predetermined floor of the building 3, and an upper support portion 12. A plurality of (here, eight) support legs 13 connected to the portion 11 and the lower support portion 12 by pin joining and arranged in a truss shape, and a brace material 14 for connecting the plurality of support legs 13 to each other are provided. ing. In addition, in FIGS. 3 and 4, the lower support portion 12 and the brace material 14 are omitted.

The upper support portion 11 is formed in a rectangular shape in a top view by a pair of horizontal members 11A and a pair of vertical members 11B, and is arranged so as to surround the mast 22 all around. The upper support portion 11 is fixed to the lower portion of the elevating device 23 shown in FIG. 1 by a fixing means (not shown) such as bolt joining. That is, the upper support portion 11 is provided so as to be relatively movable in the vertical direction along the mast 22 by driving the elevating device 23 with the mast 22 inserted inside.
A first pin locking piece 111 for pin-joining the upper end portion 13a of the support leg 13 is attached to the lower portion of the upper support portion 11.

Although H-shaped steel is used for the horizontal member 11A and the vertical member 11B in this embodiment, members having other shapes may be used. Further, the upper support portion 11 is not limited to being formed in a rectangular shape in a top view, and may have a shape framed into a circle, a hexagon, or the like in a top view.

As shown in FIG. 2, the lower support portion 12 is formed in a substantially cube having an upper surface 12a and a lower surface 12b, and is located at four locations so as to be located at the top of a quadrangle (corner portion 11a of the upper support portion 11) in a top view. Have been placed. A second pin locking piece 121 for pin-joining the lower end portion 13b of the support leg 13 is attached to the upper surface 12a of the lower support portion 12. As shown in FIGS. 3 (a) and 3 (b) and 4 (a) and 4 (b), the lower support portions 12 are detachably connected to each other with the plurality of support legs 13 by pin joining. The lower surface 12b of the lower support portion 12 is placed on the upper surface of the skeleton girder 34 (connecting frame) forming the skeleton opening and fixed with bolts or the like. The skeleton girder 34 is made of H-shaped steel arranged in parallel at predetermined intervals.

As shown in FIG. 2, the support leg 13 is made of a long steel material, and connects the upper support portion 11 and the lower support portion 12 with the longitudinal direction thereof oriented substantially in the vertical direction. The upper end portion 13a of the support leg 13 is provided with a first pin locking portion 131 that is pin-bonded to the first pin locking piece 111 of the upper support portion 11. The lower end portion 13b is provided with a second pin locking portion 132 that is pin-bonded to the second pin locking piece 121 of the lower support portion 12. Two support legs 13 are provided for each corner portion 11a of the upper support portion 11 that forms a quadrangular shape when viewed from above. The two support legs 13 provided on the corner portion 11a are connected to the first pin locking pieces 111 located on both sides of the first pin locking portion 131 sandwiching the corner portion 11a, and the respective second pins 13 are connected to each other. The locking portion 132 is connected to one second pin locking piece 121 of the lower support portion 12, which is arranged in a truss shape.

The support leg 13 configured in this way supports the upper part when the lower support portion 12 is not supported with respect to the skeleton girder 34 (the second pin locking portion 132 is detached from the second pin locking piece 121). The lower end portion 13b is provided so as to be openable and closable with the first pin locking piece 111 of the portion 11 as a fulcrum. That is, as shown in FIGS. 4A and 4B, the eight support legs 13 are folded in the vertical direction with the upper support portion 11 as the center.
3 (a) and 3 (b) show the open state R1 in which the support legs 13 are open. FIGS. 4A and 4B show a closed state R2 in which all the support legs 13 are closed so that the support gantry 1 can pass through the skeleton opening when the mast 22 is replaced.

As shown in FIG. 2, the brace material 14 is made of a long member, and of the four lower support portions 12, the facing side surfaces 12c are vertically and horizontally connected to each other, and the lower end portion of the support leg 13 separated from the lower support portion 12. 13b (lower support portion 12) is restrained by the brace material 14. The brace material 14 is detachably provided with respect to the lower support portion 12, and the brace material 14 is removed from the lower support portion 12 when the support legs 13 are opened and closed.

Next, the climbing method using the support gantry for the tower crane described above will be specifically described with reference to the drawings.

First, a method of assembling the support gantry 1 will be described. As shown in FIG. 5A, the support gantry 1 is carried to the site as a gantry unit 1A divided into two parts. The gantry unit 1A is divided into two parts, and the upper support portion 11 and the lower support portion 12 are connected by pin joints by the support legs 13. Here, as shown in FIG. 4B, the skeleton opening in which the mast 22 is arranged on the installation floor of the support gantry 1 is formed by a pair of skeleton girders 34 facing each other.

Subsequently, as shown in FIGS. 5 (b) and 5 (c), the lower support portions 12 are connected to each other by the brace material 14 for each gantry unit 1A by the ground assembly at the site, and the two gantry units 1A are ground-assembled. The lower support portion 12 is fixed on the skeleton girder 34 by bolting, and the two gantry units 1A and 1A are also fixed by bolting or welding. Subsequently, the brace material 14 is also attached in the direction along the skeleton girder 34. As a result, the assembly of the support gantry 1 is completed.
After that, as shown in FIG. 6A, the upper support portion 11 of the support gantry 1 and the elevating device 23 are connected.

As a climbing method, first, as described above, the lower support portion 12 of the support gantry 1 is supported by the skeleton girder 34 forming the skeleton opening, and the horizontal load and the vertical load acting on the mast 22 and the elevating device 23 are supported. (See FIG. 6 (a)).

After that, the fixing of the building 3 to the skeleton at the lower end of the mast 22 is released. That is, the lower end of the mast 22 is separated from the above-mentioned base frame (not shown). In this state, the mast 22 is supported only by the elevating device 23.

Subsequently, as shown in FIG. 6B, the mast 22 is raised by the elevating device 23, and the lower end of the mast is supported by the mast support pedestal 24 on the skeleton girder 34 on the floor on which the mast 22 is raised. The relocation to is completed. In the ascending operation of the mast 22 by the elevating device 23, the mast 22 is alternately gripped by the upper frame 231 and the lower frame 232 of the elevating device 23, and the elevating jack (not shown) is expanded and contracted to move up and down between the upper frame 231 and the lower frame 232. The mast 22 can be raised by sequentially repeating the operation of causing the mast 22 to be raised.

Next, as shown in FIGS. 2 and 3 (a) and 3 (b), the lower support portion 12 is separated from the mast girder 34, and as shown in FIGS. 4 (a) and 4 (b), a plurality of support legs are provided. 13 is shrunk toward the center of the mast 22 so that it can pass through the skeleton opening and closed.
Specifically, the four lower support portions 12 are separated from the skeleton girder 34, and all four brace members 14 connecting the lower support portions 12 to each other are removed. Since all eight support legs 13 are pin-joined to the upper support portion 11, the brace material 14 can be removed to allow the legs to be opened and closed. Then, each support leg 13 is brought into a state in which the lower end portion 13b thereof is contracted in a direction close to the mast 22 side (closed state R2). The support legs 13 in the closed state R2 may be in a state where they can pass through the skeleton opening. At this time, the plurality of support legs 13 are held in the closed state R2 by an appropriate holding means such as a restraining jig.

Next, as shown in FIG. 1, the support gantry 1 is raised along the mast 22 together with the elevating device 23. That is, when the crane main body 21 is replaced together with the elevating device 23, the elevating jack (not shown) provided in the elevating device 23 is extended to raise the upper frame 231 of the elevating device 23 and fix it to the mast 22. Then, the lower frame 232 is released from the mast 22, the elevating jack is contracted to raise the lower frame 232, and the lower frame 232 is fixed to the mast 22. As a result, the refilling for one stroke is completed. By repeating such refilling work, the crane main body 21 can be raised, and the elevating device 23 itself and the support gantry 1 can be relocated to the upper floor.

After that, as shown in FIG. 6B, the support legs 13 in the closed state R2 are set to the open state R1, and the lower support portion 12 is fixed on the skeleton girder 34 previously installed in the skeleton opening on the relocated floor. , Floor climbing is completed. As a result, the horizontal load and the vertical load of the crane main body 21 and the elevating device 23 are transmitted to the skeleton via the support gantry 1, and the reaction force of the crane can be applied to the skeleton via the support gantry 1.

Next, a multi-span compatible configuration capable of corresponding to the span dimensions of the skeleton girder 34 of the building 3 in the support gantry 1 according to the above-described embodiment will be described.
In the support gantry 1 of the present embodiment, the position of the lower support portion 12 can be adjusted according to the size of the skeleton opening, that is, various aspect ratios in the skeleton girder 34 by the following multi-span compatible configuration. It has become.

As one of the configurations corresponding to multi-span, as described above, since the support legs 13 of the support gantry 1 are provided so as to be openable and closable with the upper support portion 11 as a fulcrum, the support legs 13 are closed during climbing to form a skeleton. It can be passed through the opening.

As another configuration for multi-span, the frame long side dimension of the upper support portion 11 can be adjusted. That is, since the support gantry 1 is configured by combining the gantry units 1A and 1A divided into two, even if the upper support portions 11 of the gantry units 1A and 1A are directly joined as shown in FIG. 7A. However, as shown in FIG. 7B, an adjusting member 16 made of H-shaped steel or the like set to a predetermined length is inserted between the upper support portions 11 of the divided gantry units 1A and 1A. Therefore, it is possible to change the size of the upper support portion 11.
By inserting the adjusting member 16 between the gantry units 1A and 1A in this way, the installation span of the support gantry 1 can be increased. That is, the position of the lower support portion 12 of the support gantry 1 can be adjusted and installed according to the size of the skeleton opening (frame girder 34).

Further, as yet another configuration for multi-span, when the span L1 of the skeleton girder 34 shown in FIG. 8 is larger than the span L2 of the skeleton girder 34 shown in FIG. 7B described above, the upper part of the support gantry 1 is provided. It can be installed by changing the vertical and horizontal installation directions of the support portion 11. That is, in the installation method of the support gantry 1 shown in FIG. 8, the longitudinal direction in which the adjusting member 16 is inserted in the upper support portion 11 is directed in the direction orthogonal to the skeleton girder 34, so that the skeleton girder 34 having a large span is provided. It can also handle cases.

Next, the operation of the above-mentioned support gantry for tower crane and the climbing method using the above-mentioned support gantry will be described in detail with reference to the drawings.
In the present embodiment, as shown in FIG. 2, the support legs 13 are vertically connected to the upper support portion 11 by pin joining, and the lower support portion 12 of the support legs 13 is not supported with respect to the skeleton girder 34. The lower end portion 13b is provided so as to be openable and closable with the upper support portion 11 as a fulcrum. Therefore, when climbing, as shown in FIGS. 4A and 4B, the support gantry can be simply closed by shrinking the plurality of support legs 13 toward the center of the mast so that they can pass through the skeleton opening. 1 can be raised along the mast 22 together with the lifting device 23. In particular, in the present embodiment, the support legs 13 can be closed and climbing can be easily performed without interfering with the girders on the upper floors.

In the present embodiment, if the skeleton and the support legs 13 do not interfere with each other during climbing, the work of closing the support legs 13 is not necessary. That is, when the skeleton and the support legs 13 do not come into contact with each other, it is possible to climb with the support legs 13 spread out. In this case, it is a simple operation of attaching and detaching the skeleton and the lower support portion 12.

As described above, in the present embodiment, the crane main body 21 (and the elevating device 23) and the support gantry 1 can be moved integrally, so that the support gantry and the crane main body are separate bodies as in the conventional case. As in the case, it is possible to reduce the trouble of relocating the support gantry separately from the crane main body, and it is possible to improve the work efficiency of climbing.

Further, in the present embodiment, since the support legs 13 have a structure that can be opened and closed with the upper support portion 11 as a fulcrum, the position of the lower support portion 12 provided under the support legs 13 is the size of the skeleton opening (the skeleton girder). It can be adjusted according to the conditions of the building frame such as 34 spans). Therefore, it is possible to realize a divertable support gantry 1 having excellent versatility in installation, eliminating the need to design and manufacture the support gantry 1 according to the site, and reducing the labor and cost required for design and manufacture. Can be done.

Further, in the present embodiment, since the support legs 13 have a truss structure, the structure is strong against compression corresponding to the vertical load received from the crane main body 21, so that the weight of the member can be reduced as compared with the conventional case. , Weight reduction can be achieved.

Moreover, in the present embodiment, by making the support legs 13 have a truss structure, it can be installed even on a large spanned girder forming the skeleton girder 34.

Further, in the present embodiment, since the support floor of the support gantry 1 and the building skeleton is only one floor, the number of reinforcement points of the skeleton opening can be reduced, and the number of climbing can be reduced. , The efficiency of the refilling work can be improved.

Further, in the present embodiment, the skeleton opening can be reinforced by the skeleton girder 34, and a strong structure in which the lower support portion 12 is connected to the skeleton girder 34 in which the skeleton opening is reinforced can be realized.

Further, in the present embodiment, by keeping the support legs 13 compactly closed after climbing, it is possible to prevent the support gantry 1 from interfering with the construction, and also to suppress the wind load received by the support gantry 1. Can be done.

As described above, the tower crane support gantry according to the present embodiment and the climbing method using the support gantry can improve the work efficiency of climbing and reduce the cost.

Although the support gantry for a tower crane according to the present invention and the embodiment of the climbing method using the same have been described above, the present invention is not limited to the above embodiment and can be appropriately changed without departing from the spirit thereof. Is.

For example, the shape of the upper support portion 11 of the support gantry 1 is not limited to a quadrangle when viewed from above, and other shapes may be adopted. For example, as shown in FIG. 9, the upper support portion 11C formed in an octagonal shape may be used.

Further, the brace material 14 that connects the lower support portions 12 to each other may be provided with an expansion / contraction device that expands / contracts the brace material 14 in the length direction. As the telescopic device, for example, a hydraulic jack or the like can be adopted.
In this case, by expanding and contracting the brace material 14, the lower end portion 13b of the support leg 13 separated from the lower support portion 12 can be restrained by the brace material 14. That is, by adjusting the length of the brace material 14, it is possible to determine the folded shape of the support legs 13. That is, since the distance between the lower support portions 12 can be adjusted by expanding and contracting the brace material 14, the support gantry 1 can be installed according to the installation span of the lower support portion 12.

Further, in the present embodiment, both the upper end portion 13a and the lower end portion 13b of the support leg 13 are connected to the upper support portion 11 and the lower support portion 12 by pin joining, respectively, but the present invention is not limited to this. Instead of pin-joining, the lower support portion 12 may be connected in a non-rotatable state by bolt-joining or welding. In short, the support legs 13 need to be pin-joined to at least the upper support portion 11.

Further, in the present embodiment, the lower support portion 12 is directly fixed to the skeleton girder 34 forming the skeleton opening, but it can also be fixed via a reinforcing frame installed in the skeleton opening. For example, the lower support portion 12 may be fixed on the skeleton girder 34 of the skeleton opening.

Further, the configurations such as the dimensions and quantity of each of the upper support portion 11, the lower support portion 12, and the support legs 13 of the support gantry 1 include the shape and dimensions of the mast 22, the size and shape of the skeleton girder 34, and the tower crane 2. It can be changed as appropriate according to the conditions such as specifications.

Further, the support gantry 1 is divided into two gantry units 1A and 1A as in the above-described embodiment, but the support gantry 1 is not limited to being unitized in this way and can be assembled on site. It doesn't matter. Further, the number of divisions can be set arbitrarily.

In addition, it is possible to replace the components in the above-described embodiment with well-known components as appropriate without departing from the spirit of the present invention.

1 Support gantry (support gantry for tower crane)
1A gantry unit 2 tower crane 3 building 11 upper support 12 lower support 13 support legs 13a upper end 13b lower end 14 brace material 21 crane body 22 mast 23 lifting device 34 skeleton girder (connecting frame)
R1 open state R2 closed state

Claims (4)

It is a support gantry for tower cranes that supports the horizontal load and vertical load acting on the lifting device for raising and lowering the mast by taking reaction force on the crane body of the tower crane.
An upper support portion that is detachably supported by the mast and
A lower support part that is detachably supported by the skeleton opening on the specified floor of the building,
A plurality of support legs connected to at least the upper support portion of the upper support portion and the lower support portion by pin joining and arranged in a truss shape are provided.
The support leg for a tower crane is characterized in that the lower end portion is openable and closable with the upper support portion as a fulcrum when the lower support portion is not supported with respect to the skeleton opening. .. The support gantry for a tower crane according to claim 1, wherein the lower support portion detachably supports the plurality of support legs and is connected to a connecting frame forming the skeleton opening. The support gantry for a tower crane according to claim 1 or 2, wherein the lower support portion connects the plurality of support legs to each other and is provided with a brace material that can expand and contract in the connecting direction. A climbing method using the support gantry for a tower crane according to any one of claims 1 to 3.
A step of supporting the lower support portion of the support gantry for a tower crane to the skeleton opening to support a horizontal load and a vertical load acting on the mast and the elevating device.
The process of releasing the fixation of the mast to the skeleton of the building at the lower end of the mast,
A step of raising the mast by the elevating device and fixing the mast to the raised skeleton opening on the raised floor.
A step of separating the lower support portion from the skeleton opening and shrinking and closing the plurality of support legs toward the mast center so as to be able to pass through the skeleton opening.
A step of raising the tower crane support gantry together with the elevating device along the mast, and
A climbing method using a support gantry for a tower crane, which is characterized by having.

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