JPH11180675A - Lifting device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To equally apply load to respective lifting members for lifting a structure at three or more points in simple structure. SOLUTION: Fixed pulleys 3a, 4a of equalizers 3, 4 are rotatably and individually supported on both ends of a balance beam 5, and both ends of the suspending members 3b, 4b having the intermediate parts laied on respective fixed pulleys 3a, 4a are individually locked on anchor bolts 2a to 2d of a reinforced concrete structure 1. Moreover, both ends of a lifting wire 6 are individually locked on a plurality of hooks 5a, 5b provided on the balance beam 5, and the central part in the longitudinal direction of the lifting wire 6 is locked on a crane side hook 7. The crane is operated, and the crane side hook 7 lifts the reinforced concrete structure 1 through the wire 6, the balance beam 5, a plurality of equalizers 3, 4 and the anchor bolts 2a to 2d.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an apparatus for lifting a structure at three or more points.

[0002]

2. Description of the Related Art Reinforced concrete structures such as reinforced concrete columns are manufactured on site by sequentially performing a reinforcing work, a formwork assembling work, and a concrete placing work in order to shorten a building construction period and reduce costs. It is known that a young reinforced concrete structure, which has just been manufactured, is lifted and constructed. FIG. 4 shows a conventional lifting device for the young reinforced concrete structure 1, in which one end of three suspension members 11, 12, 13 having lever blocks 11a, 12a, 13a has a reinforced concrete structure. Moored at three points at the middle and both ends of body 1,
The other end of each of the suspension members 11 to 13 is moored to a balance beam 14 made of steel, and each of the lever blocks 11 a
13a, the distance from the balance beam 14 of each of the suspension members 11 to 13 to the reinforced concrete structure 1 is set to be substantially equal, and the suspension wire 1 is connected to the balance beam 14.
5 is moored at both ends, and a central portion in the length direction of the suspension wire 15 is lifted by a crane-side hook 16.

[0003]

However, in the above-mentioned conventional lifting device, a plurality of lifting members 1
When any one of 1 to 13 is loosened and the hanging load is not evenly applied to each of the hanging members 11 to 13 and the object to be lifted is the young reinforced concrete structure 1, the cast concrete is completely Since the concrete was not solidified, the concrete of the reinforced concrete structure 1 was sometimes cracked. When a crack is formed, the reinforced concrete structure 1 is discarded without being used.
By the way, Japanese Patent Application Laid-Open No. Hei 6-144774 discloses a lifting device for a precast concrete structure. This lifting device vertically connects one endless suspension member to a plurality of fixed pulleys and a plurality of moving pulleys. It is a complicated structure wound around in a meandering manner.

Accordingly, an object of the present invention is to provide a lifting device having a simple structure capable of uniformly applying a lifting load to each of the lifting members for lifting the structure at three or more points.

[0005]

In the lifting apparatus according to the first aspect of the present invention, an intermediate portion of a hanging member such as a chain or a wire for lifting the structure at three or more points is connected to a constant pulley on the crane side. It is characterized by a combination of multiple hung equalizers. In the lifting device according to the second aspect of the invention, the plurality of combinations of the equalizers according to the first aspect support the constant pulleys of the plurality of equalizers by a balance beam disposed between the crane and the plurality of equalizers. In this configuration, both ends of the suspender of the ecologicalizer are individually moored to the structure. In the lifting device according to the third aspect of the present invention, the plurality of combinations of the equalizers according to the first aspect anchor both ends of the suspension member of one of the equalizers to the structure, and The constant pulley is supported at one end of the suspension member of the other equalizer, the other end of the suspension member of the other equalizer is moored to the structure, and the constant pulley of the other equalizer is further moved on the crane side. It is characterized in that it is supported.

[0006]

FIG. 1 shows a side view of a first embodiment of the present invention, wherein 1 is a young reinforced concrete structure produced on site, 2a, 2b, 2c and 2d are suspensions of the reinforced concrete structure 1. Anchor bolts attached to four points on the side, 3, 4 are a plurality of equalizers, 5 is a balance beam, 6 is a fixed-length hanging wire, and 7 is a crane-side hook. Each of the equalizers 3 and 4 includes a fixed pulley 3a,
4a and a fixed length suspension member 3 such as a chain or a wire
b, 4b. Each of the anchor bolts 2a to 2d is screw-fitted to a nut (not shown) embedded when the reinforced concrete structure 1 is manufactured.

In this embodiment, the fixed pulleys 3a and 4a of each of the equalizers 3 and 4 are individually supported rotatably at both ends of the balance beam 5, and an intermediate portion is wound around each of the constant pulleys 3a and 4a. Both ends of the suspended suspension members 3b, 4b are individually moored to the anchor bolts 2a to 2d of the reinforced concrete structure 1. Further, both ends of the suspension wire 6 are individually moored to a plurality of hooks 5 a and 5 b provided on the balance beam 5, and a central portion in the length direction of the suspension wire 6 is moored to the crane-side hook 7. In this state, by operating a crane (not shown), the hook 7 on the crane side causes the hanging wire 6, the balance beam 5, the plurality of
And the reinforced concrete structure 1 is lifted via the anchor bolts 2a to 2d. Then, the suspension members 3b, 4b of each of the equalizers 3, 4 are moved from the reinforced concrete structure 1.
, The constant pulleys 3a, 4a of each of the equalizers 3, 4 rotate freely, and the hanging members 3b, 4b are stretched evenly without loosening, and the anchor bolts of each of the equalizers 3, 4 The suspension loads on the four suspension points according to 2a to 2d become uniform. Therefore, although it is a simple structure using a plurality of the equalizers 3 and 4, even if the object to be lifted is a young reinforced concrete structure 1 that is cast in place, it is possible to eliminate the inconvenience of cracking the concrete. .

FIG. 2 shows a side view of a second embodiment of the present invention, in which a young reinforced concrete structure 1 is lifted at three points by two equalizers 3 and 4. In the reinforced concrete structure 1, three anchor bolts 2a to 2c are arranged. Then, both ends of the suspending member 3b of one equalizer 3 in the lifting device are individually moored to the two anchor bolts 2a, 2b of the reinforced concrete structure 1, and the fixed pulley 3a of this one equalizer 3 is connected to another one.
Supported at one end of the suspending member 4b of the two equalizers 4,
The other end of the suspending member 4b of the other equalizer 4 is moored to the remaining one anchor bolt 2c of the reinforced concrete structure 1, and the constant pulley 4a of the other equalizer 4 is supported by the crane-side hook 7. doing. In this state, by operating a crane (not shown), the crane-side hook 7 lifts the reinforced concrete structure 1 via the plurality of equalizers 3 and 4 and the anchor bolts 2a to 2c, as in the first embodiment. In addition, the suspending members 3b, 4b of each of the equalizers 3, 4 are in a state of being evenly stretched without loosening, and each of the equalizers 3, 4 has an equal suspending load to the three suspending points by the anchor bolts 2a to 2c. Become. Therefore, multiple equalizers 3, 4
However, it is possible to eliminate the inconvenience of cracking the concrete of the young reinforced concrete structure 1 while having a simple structure using.

In each of the above embodiments, the young reinforced concrete structure 1 is lifted at four or three points by the two equalizers 3 and 4, but may be lifted at five or more points by using three or more equalizers. good. For example, FIG. 3 shows a side view of the third embodiment in which three equalizers 3, 4, and 8 are used for lifting at five points. The reinforced concrete structure 1 is provided with five anchor bolts 2a to 2e. Then, the suspension member 3 of one of the equalizers 3 in the lifting device
b are individually moored to the two anchor bolts 2a and 2b of the reinforced concrete structure 1, and the constant pulley 3a of the one equalizer 3 is supported by one end of the suspension member 4b of the other equalizer 4. The other end of the suspending member 4b of the other equalizer 4 is moored to one anchor bolt 2c of the reinforced concrete structure 1, and the other
The constant pulleys 4a of the two equalizers 4 are rotatably supported on one end of the balance beam 5. Further, both end portions of the suspension member 8b of the remaining one equalizer 8 are individually moored to the remaining two anchor bolts 2d and 2e of the reinforced concrete structure 1, and the fixed pulley 8a of the remaining one equalizer 8 is removed. The other end of the balance beam 5 is rotatably supported. Then, the balance beam 5 is connected to the plurality of hooks 5a, 5a.
b is supported via the suspension wire 6 and the crane side hook 7, and by operating a crane (not shown), the crane side hook 7 is connected to the suspension wire 6, the balance beam 5, the three equalizers 3, 4, 8 and the anchor. When the reinforced concrete structure 1 is hoisted via the bolts 2a to 2e, the respective equalizers 3, 4, and 8 are lifted similarly to the first and second embodiments.
Of the suspension members 3b, 4b, and 8b are uniformly stretched without loosening, and the suspension loads of the equalizers 3, 4, and 8 at the five suspension points by the anchor bolts 2a to 2e become uniform. Therefore, multiple equalizers 3, 4, 8
However, it is possible to eliminate the inconvenience of cracking the concrete of the young reinforced concrete structure 1 while having a simple structure using.

[0010]

According to the first aspect of the present invention, a plurality of equalizers in which a middle portion of a hanging member such as a chain or a wire for lifting a structure at three or more points is hung on a fixed pulley on a crane side are combined. Therefore, when the structure is lifted, the constant pulley of each equalizer rotates freely due to the load acting on the suspension member of each equalizer from the structure, and each suspension member is stretched evenly without loosening. In addition, the lifting load on three or more hanging points between each equalizer and the structure becomes uniform. Therefore, even if the structure to be lifted is a young reinforced concrete structure, it is possible to eliminate the inconvenience of cracking the concrete, even though the structure is a simple structure using a plurality of equalizers. According to the invention of claim 2, the constant pulleys of the plurality of equalizers are individually supported by the balance beam, and both ends of the suspension members of these equalizers are individually moored to the structure, thereby lifting the structure. In this case, due to the load acting on the suspension member of each equalizer from the structure, the pulleys of each equalizer rotate freely, and each suspension member is stretched evenly without loosening, and each And the suspension load on the three or more suspension points becomes uniform. Therefore, even though the structure to be lifted is a young reinforced concrete structure, although it is a simple structure using a plurality of equalizers,
The inconvenience of cracking the concrete can be eliminated. According to the invention of claim 3, both ends of one suspension member of the plurality of equalizers are moored to the structure, and the fixed pulley of one of the equalizers is connected to one end of the suspension member of the other equalizer. When the structure is lifted by supporting the other end of the hanging member of the other equalizer to the structure and supporting the constant pulley of the other equalizer on the crane side, each structure is lifted from the structure. Due to the load acting on the hanging members of the equalizer, the pulleys of each equalizer rotate freely and each hanging member is stretched evenly without slack, and each equalizer is suspended at three or more points with the structure. The suspension load on the point becomes uniform. Therefore, even if the structure to be lifted is a young reinforced concrete structure, it is possible to eliminate the inconvenience of cracking the concrete, even though the structure is a simple structure using a plurality of equalizers.

[Brief description of the drawings]

FIG. 1 is a side view of a first embodiment of the present invention.

FIG. 2 is a side view of a second embodiment of the present invention.

FIG. 3 is a side view of a third embodiment of the present invention.

FIG. 4 is a side view of a conventional lifting device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Reinforced concrete structure 3,4,8 Equalizer 5 Balance beam 6 Suspension wire 7 Crane side hook

Claims (3)

[Claims] 1. A lifting device comprising a plurality of equalizers in which a middle portion of a hanging member such as a chain or a wire for lifting a structure at three or more points is mounted on a constant pulley on a crane side. 2. A plurality of combinations of the equalizers support the fixed pulleys of the plurality of equalizers with a balance beam disposed between the cranes, and individually connect both ends of the hanging members of the plurality of equalizers to the structure. The lifting device according to claim 1, wherein the lifting device is moored. 3. A plurality of combinations of equalizers anchor both ends of a suspension member of one of the equalizers to a structure,
The pulley of one of the equalizers is supported at one end of a suspending member of the other equalizer, and the other end of the suspending member of the other equalizer is moored to a structure. The lifting device according to claim 1, wherein the constant pulley is supported on the crane side.