JP2839380B2 - Crane dismantling method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a crane jib disassembling method in which a tip jib is detachably connected to a root jib connected to a crane body.

[0002]

2. Description of the Related Art A conventional crane jib disassembling method has been configured as shown in a side view of FIG. 6 and a plan view of FIG.

[0003] That is, a tip side jib 03 is releasably connected to a root jib 02 connected to the crane main body 01, and the tip side of the tip side jib 03 is unrolled by unwinding the hoisting wire 04. 05, and in this state, the hook 06 of the demolition crane is hung on the tip side jib 03 to be suspended and supported.
The connection between the jib 2 and the tip side jib 03 is released, the tip side jib 03 is first disassembled, and then the root jib 02 and the crane main body 01 are disassembled.

[0004]

However, in the prior art, since the length of the tip side jib 03 is long, depending on the frame, the shape of the rooftop is rectangular. There is a drawback that the efficiency of the disassembling operation is reduced due to the restriction on the place where the jib receiving stand 05 to be supported is installed.

Further, the hook 06 of the dismantling crane must be located above the center of gravity of the tip side jib 03.
2 and the crane body 01 are also dismantled.
The hook 06 must be able to move even above the position of the center of gravity of the crane main body 01, and a large crane for dismantling that has a relatively long jib is required, and dismantling of the dismantling crane requires time and effort. There was a drawback that the workability was reduced.

[0006] The present invention has been made in view of such circumstances, and an object thereof is to improve the jib structure and to efficiently dismantle a crane using a small dismantling crane.

[0007]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention provides a crane jib disassembling method in which a tip side jib is detachably connected to a root jib connected to a crane body. The side jib is configured to be bendable into a first jib on the distal end side and a second jib on the root jib side by releasing the connection at the connection portion at an intermediate position in the longitudinal direction, and the crane body and the The temporary fixing wire is connected to the second jib, the connection at the connecting portion is released, the undulating wire connected to the first jib is rewound, and the first jib falls down and down around the connecting portion. Next, the temporary fixing wire is rewound, the tip side of the first jib is moved to the crane body side, and is folded back below the second jib, and the second jib side of the first jib is supported by the jib support. Let it be folded 1 and a hook for dismantling a crane suspended supporting and hanging balls to the second jib, to release the connection between the base jib and the second jib.

[0008]

According to the construction of the crane jib disassembling method of the present invention, the first jib is folded back so as to overlap below the second jib, and the center of gravity of the folded first and second jib is raised. The hook of the crane for dismantling is moved to a considerable place, the connection between the second jib and the root jib is released, and the first and second jib constituting the distal end jib can be disassembled.

[0009]

FIG. 1 is a side view of a crane, in which a root jib 2 is connected to a crane main body 1 so as to be able to move up and down. The side jib 4 is connected, and the hoisting wire 5 is connected between the tip side of the tip side jib 4 and the crane main body 1.

The distal jib 4 is connected to the first jib 4a on the distal end side and the second jib 4 on the base jib 2 side via a second connection portion 6 which can be disconnected at an intermediate position in the longitudinal direction. And a jib 4b.

With the above arrangement, the crane jib can be dismantled as follows.

That is, the tip side jib 4 is folded down, and FIG.
As shown by a two-dot chain line, the temporary fixing wire 7 is connected between the distal end side of the second jib 4b and the crane main body 1, and the connection at the second connecting portion 6 is released.

Next, the temporary fixing wire 7 is wound up in a state where the undulating wire 5 is unwound and loosened, and the first jib 4a is moved downward around the second connecting portion 6 as shown in the side view of FIG. Let it fall down.

Thereafter, the temporary fixing wire 7 is rewound and the first jib 4a is laid down in a suspended state, and as shown in the side view of FIG. 3 and the plan view of FIG. Move the tip side to the crane body 1 side
Of the first jib 4a, and the jib support 8 supports the second jib 4b side of the first jib 4a.

Then, as shown in the side view of FIG. 5, a hook 9 of a dismantling crane is slung on the first and second jib 4a, 4b in the folded state, suspended and supported, and the undulating wire 5 and the temporary support are provided. The wire 7 is removed, and the connection between the root jib 2 and the second jib 4b is released.

Thereafter, the folded back first and second jib 4a, 4b are transported to an appropriate place and dismantled. Thereafter, the root jib 2 and the crane main body 1 are also removed by the dismantling crane. And dismantle it to a size that can be taken down by a lift or the like.

After that, the crane for dismantling is finally dismantled,
It is lowered by a lift or the like to complete a series of dismantling work.

[0018]

According to the crane jib disassembling method of the present invention, since the first jib is folded back to the crane body side, the center of gravity of the folded first and second jib can be brought closer to the crane body side. The distance from the center of gravity of the crane body is shortened, and the crane for dismantling can be dismantled with a small crane having a short jib. became.

Also, since the second jib end of the first jib is supported by the jib receiving base in a state where the first and second jib are turned back, the jib is located closer to the crane body than in the prior art. The cradle can be installed, and there are few restrictions on the installation position of the jib cradle. Even if the rooftop of the skeleton is rectangular, demolition work can be performed efficiently, and workability can be improved. Was.

[Brief description of the drawings]

FIG. 1 is a side view of a crane.

FIG. 2 is a side view of the crane.

FIG. 3 is a side view of the crane.

FIG. 4 is a plan view of the crane.

FIG. 5 is a side view of the crane.

FIG. 6 is a side view of a conventional crane.

FIG. 7 is a plan view of a conventional crane.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Crane main body 2 Root jib 4 Tip side jib 4a 1st jib 4b 2nd jib 5 Undulating wire 6 2nd connection part 7 Temporary fixing wire 8 Jib receiving stand 9 Hook of crane for dismantling

──────────────────────────────────────────────────続 き Continued on front page (58) Field surveyed (Int. Cl. ⁶ , DB name) B66C 19/00-23/94

Claims (1)

(57) [Claims] 1. A jib disassembling method for a crane in which a tip side jib is detachably connected to a root jib connected to a crane main body, wherein the tip side jib is connected at a connecting portion at an intermediate position in a longitudinal direction thereof. The crane body is configured to be bendable into the first jib on the distal end side and the second jib on the root jib side by releasing the hook, and the temporary fixing wire is connected across the crane body and the second jib, and the connection is performed. Disconnecting the connection at the part, unwinding the undulating wire connected to the first jib, causing the first jib to fall down and down around the connecting portion, and then unwinding the temporary fixing wire; Moving the tip end side of the first jib toward the crane body side and turning it back below the second jib, and supporting the second jib side of the first jib on a jib receiving stand;
A jib disassembling method for a crane, comprising: hanging a hook of a dismantling crane on the first and second jib in a folded state, suspending and supporting the hook, and releasing the connection between the root jib and the second jib. .