JP7334022B1 - PC steel lifting jig - Google Patents

Abstract

An object of the present invention is to provide a PC steel material lifting jig that can fix and lift a PC steel material at any position. [Solution] In a PC steel material lifting jig 1 for fixing a PC steel material P1 and hoisting it by hooking it to a hook of a lifting machine, a tapered notch hole that corresponds to the outer shape of a wedge 4 and whose diameter decreases as it goes downward is provided. The jig body 2 is provided with a jig body 2 having a jig body 21 and a presser plate 5 for pressing and fixing a wedge 4 to the jig body 2, and the presser plate 5 and the jig body 2 are removably joined with bolts. [Selection diagram] Figure 2

Description

TECHNICAL FIELD The present invention relates to a jig for lifting PC steel materials, and more particularly to a jig for lifting a strand of PC steel wire.

2. Description of the Related Art Conventionally, large-span PC (Prestressed Concrete) structures have been constructed by introducing prestress to buildings and structures by a post-tension method such as VSL (Vorspun System Losinger) method.

In such a VSL construction method, a tension fixture is attached to the formwork and reinforcing bars of the PC structure, a sheath pipe is laid, a strand of PC steel wire is inserted into the sheath pipe, and concrete is poured until the concrete reaches a predetermined level. After the intensity of tension is expressed, pre-stress is introduced. For this reason, it is necessary to lift the PC steel material such as the PC steel wire stranded wire from the carrying-in place to a predetermined position by a lifting machine such as a crane and transport it. In addition, PC steel materials are necessarily long and heavy because they can only be connected by a suitable joint method capable of withstanding the tension force of prestress.

In addition, if the PC steel material is damaged by mistake, it may break due to the damage when the tension force is introduced. Therefore, a lifting jig capable of lifting the PC steel material without damaging the PC steel material has been desired. Conventionally, as a lifting jig for a PC steel material, there is a lifting jig in which an end portion of a long PC steel material is inserted into a hole of the jig to be mounted and lifted. However, since conventional PC steel lifting jigs lift one end of a long PC steel and lift the entire length of the PC steel, the lifting distance is inevitably long, requiring a larger lifting machine. In other words, not only is the cost of the hoisting machine increased, but problems have arisen such as being unable to carry the hoisting machine to the construction site or securing a space for installing the hoisting machine. For this reason, there has been a strong demand for a PC steel material lifting jig that can fix and lift the PC steel material at an arbitrary position, such as near the center in the length direction.

For example, Patent Literature 1 discloses a fitting for construction of a PC structure, which has an upper end that is fixed to a guide cable and a lower end that is provided with a mounting portion for mounting core wires of each PC steel strand of a PC steel strand bundle. (Claim 3 and 4 of the patent document 1, paragraph [0022] of the specification, see FIGS. 1 and 2 of the drawings, etc.).

However, the fitting for construction of the PC structure described in Patent Document 1 requires a long lifting distance because the connecting fitting 40 is attached to one end of the wire bundle 30 made of PC steel and the entire length of the wire bundle 30 is lifted from the PC steel. , a larger lifting machine is required. In other words, as described above, not only does the cost of the hoisting machine increase, but it is also difficult to bring the hoisting machine to the construction site and to secure the space for installing the hoisting machine. I couldn't do it.

As a prior art of other lifting jigs, for example, in Patent Document 2, it is suspended by a suspension device via a suspension wire 30, and is connected to the upper part of the column 10 to be suspended, A support member 20 having at least three suspension members for suspending the column reinforcement 10 is provided, and the positional relationship between the outer diameter of the preassembled column reinforcement and the wire directly suspending the column reinforcement can be appropriately adjusted. A hanging jig for column reinforcement is disclosed (see claim 1 of the scope of claim of patent document 2, paragraphs [0018] to [0028] of the specification, FIG. 2 of the drawings, etc.).

However, the lifting jig for the column reinforcement described in Patent Document 2 can fix and lift the PC steel material near the center in the longitudinal direction at an arbitrary position, like the conventional PC steel material lifting jig described above. However, there is a problem that the lifting distance is inevitably long, and the demerit caused by an increase in the size of the lifting machine cannot be resolved.

JP 2011-241633 A JP 2019-167762 A

SUMMARY OF THE INVENTION Accordingly, the present invention has been devised in view of the above-mentioned problems, and its object is to provide a PC steel material lifting jig capable of fixing and lifting a PC steel material at an arbitrary position. be.

A PC steel material lifting jig according to claim 1 is a PC steel material lifting jig for fixing a PC steel material and hooking it to a hook of a lifting machine to lift it, and the diameter decreases as it goes downward corresponding to the outer shape of the wedge. a jig body having a tapered notch hole for holding the wedge, and a holding plate for pressing and fixing the wedge to the jig body, wherein the holding plate and the jig body are detachably bolted. The jig body is formed with a female screw portion for mounting an over-tightening prevention bolt .

The prestressing steel material lifting jig according to claim 2 is the prestressing steel material lifting jig according to claim 1, wherein a lifting plate having a lifting hole formed is attached to an end portion of the jig body. Characterized by

According to the invention according to claim 1 or 2 , the PC steel material can be lifted by fixing it at an arbitrary position such as the end portion in the longitudinal direction or the vicinity of the central portion. Therefore, not only is the usability improved when lifting with a heavy lifting machine, but also the problem of a long lifting distance can be solved. In addition, this eliminates the need for a large hoist, and solves the problems of increased cost of the hoist, the problem of carrying the hoist to the construction site, and the problem of the installation space for the hoist.
Moreover, according to the invention of claim 1 or 2, since the jig body is formed with a female threaded portion for mounting the overtightening prevention bolt, the overtightening prevention bolt can be attached to the holding plate and the jig. It is possible to adjust the distance from the fixture body. Therefore, it is possible to prevent the wedge from being damaged by over-tightening the bolt that joins the pressing plate and the jig body bolt.

In particular, according to the second aspect of the invention, since a hanging plate having a hanging hole is attached, it is easy to hook the PC steel material lifting jig to the hook of the crane using a shackle or the like. be.

FIG. 1 is a plan view showing a PC steel material lifting jig according to an embodiment of the present invention. FIG. 2 is a cross-sectional view taken along the line AA of FIG. 1 showing the same PC steel material lifting jig. FIG. 3 is a perspective view showing a jig body of the same PC steel material lifting jig. FIG. 4 is a front view showing the same jig main body. FIG. 5 is a plan view showing the jig main body of the same. FIG. 6 is a bottom view showing the jig main body of the same. FIG. 7 is a side view showing the same jig main body. FIG. 8 is a perspective view showing a pair of holding plates of the same PC steel material lifting jig. FIG. 9 is a plan view showing a pair of holding plates of the same PC steel material lifting jig. FIG. 10 is a photograph showing a state in which the ends of the PC steel material are fixed by the same PC steel material lifting jig and lifted by a lifting machine. FIG. 11 is a photograph showing a state in which the middle portion of the PC steel material is fixed by the same PC steel material lifting jig and lifted by a lifting machine.

Hereinafter, one embodiment of a jig for lifting PC steel materials according to the present invention will be described in detail with reference to the drawings.

<PC steel lifting jig>

First, a PC steel material lifting jig 1 according to an embodiment of the present invention will be described with reference to FIGS. 1 to 9. FIG. A prestressing steel material lifting jig 1 according to an embodiment of the present invention is a jig for fixing a prestressing steel material P1 and hooking it onto a hook of a lifting machine so as to lift it with a lifting machine such as a crane. FIG. 1 is a plan view showing a PC steel material lifting jig 1 according to an embodiment of the present invention, and FIG. 2 is a cross-sectional view showing the PC steel material lifting jig 1 taken along the line AA in FIG.

As shown in FIGS. 1 and 2, the PC steel material lifting jig 1 comprises a jig body 2 serving as a base, a lifting plate 3 attached to the jig body 2, and a PC steel material P1, which are clamped and fixed. and a pressing plate 5 for pressing and fixing the wedges 4 to the jig body 2, and the like.

(jig body)
As shown in FIGS. 3 to 7, the jig main body 2 is a member having a main body plate 20 as a base made of a 32 mm thick rectangular steel plate made of general structural rolled steel SS400 specified in JIS G310. 3 is a perspective view showing the jig body 2 of the PC steel material lifting jig 1, and FIG. 4 is a front view showing the jig body 2. As shown in FIG. 5 is a plan view showing the jig body 2, FIG. 6 is a bottom view showing the jig body 2, and FIG. 7 is a side view showing the jig body 2. As shown in FIG.

Of course, the body plate 20 is not limited to the general structural rolled steel material SS400, and may be made of other steel material. However, in order to use the PC steel material lifting jig 1 repeatedly, it is preferable to have a certain degree of hardness so that it can hold even if it rubs against the PC steel material P1.

In addition, the body plate 20 has a plurality of truncated cones (in the illustrated form, 2 rows x 6 locations = 12 locations) for latching the wedges 4 corresponding to the shape (outer shape) of the outer surface of the truncated cone of the wedges 4 . ) are formed. The cutout hole 21 has a tapered wedge abutting portion 21a that is in close contact with the outer surface of the wedge 4 and hooks the wedge 4. The wedge abutting portion 21a decreases in diameter as it goes downward. and a notch portion 21b for inserting the .

In the vicinity of both ends of the body plate 20 in the longitudinal direction, there are formed four bolt holes 22, each of which is two pairs of through holes for bolting the pressing plate 5. As shown in FIG. Therefore, the pressing plate 5 and the jig main body 2 can be attached and detached by bolts 6, which will be described later. At both ends of the body plate 20 in the longitudinal direction outside each of the two pairs of bolt holes 22, female threaded portions 24 for mounting overtightening prevention bolts 23 made of M10 are formed.

(hanging plate)
A hanging plate 3 is attached to the end of the body plate 20 in the longitudinal direction. Specifically, the suspension plate 3 is joined to the longitudinal end portion of the body plate 20 by all-around fillet welding.

Similar to the jig body 2, the suspension plate 3 is a plate whose base is a plate body 30 made of a 12 mm-thick rectangular steel plate made of general structural rolled steel SS400. The plate body 30 is provided with a hanging hole 31 having a diameter of 20 mm for inserting a shackle or the like to be hooked on a hook of a heavy lifting machine.

(wedge)
As shown in FIG. 2, the wedge 4 is for sandwiching and fixing the PC steel material P1, and has a truncated half conical shape with a hole for inserting the PC steel material P1.

(Presser plate)
Next, the pressing plate 5 will be described with reference to FIGS. 8 and 9. FIG. 8 is a perspective view showing a pair of holding plates 5, 5 of the PC steel material lifting jig 1, and FIG. 9 is a plan view showing a pair of holding plates 5, 5. As shown in FIG.

As shown in FIGS. 8, 9, and 2, the pressing plate 5 is a pair of left-right symmetrical members. It has the function of attaching and fixing.

Similar to the jig main body 2, the holding plate 5 is a plate whose base is a plate main body 50 made of a 16 mm-thick rectangular steel plate made of general structural rolled steel SS400. A plurality of (six in the illustrated embodiment) notches 51 through which the PC steel P1 is inserted are formed (see also FIG. 2).

Bolt holes 52, 52 for inserting the jig body 2 and M16 bolts 6 are provided at both ends of the plate body 50 in the longitudinal direction at positions corresponding to the bolt holes 22 of the jig body 2 described above. is perforated.

<How to use the PC steel lifting jig>
Next, using FIGS. 1, 2, 10 and 11, a method of using the above-described PC steel material lifting jig 1 will be described. FIG. 10 is a photograph showing a state in which the ends of the PC steel material P1 are fixed by the PC steel material lifting jig 1 and lifted by a crane, and FIG. is fixed and lifted by a crane.

As shown in FIGS. 1 and 2, a half-split wedge 4 is fitted to a PC steel material P1, and the PC steel material P1 with the wedge 4 mounted thereon is shaped into a truncated cone shape corresponding to the outer shape of the wedge 4, respectively. It is inserted through the notch hole 21 .

Then, by inserting the bolts 6 through the bolt holes 52 of the holding plate 5 and the bolt holes 22 of the jig body 2 and tightening the nuts, the holding plate 5 is bolted to the jig body 2 to connect the wedges 4 to the jig body 2 . It is pressed against a tapered wedge abutting portion 21a that decreases in diameter as it goes below the notch hole 21 in the bottom and is fixed.

At this time, since the jig main body 2 is formed with a female screw portion 24 for mounting the overtightening prevention bolt 23 , the overtightening prevention bolt 23 is used to connect the pressing plate 5 and the jig main body 2 together. Spacing can be adjusted. Therefore, it is possible to prevent the wedge 4 from being damaged by over-tightening the bolt 6 .

Then, as shown in FIGS. 10 and 11, with the wedge 4 fixed, a shackle or the like is used in the suspension hole 31 of the suspension plate 3, and a wire rope is hooked to the hook of the crane to fix the PC steel material P1. The PC steel material lifting jig 1 is lifted.

At this time, since the PC steel material lifting jig 1 can be fixed at an arbitrary position on the PC steel material P1 to which the wedge 4 is attached, it is also possible to lift the longitudinal end of the PC steel material P1 as shown in FIG. Alternatively, as shown in FIG. 11, an intermediate portion such as the vicinity of the central portion in the longitudinal direction of the PC steel material P1 can be lifted.

According to the prestressing steel material lifting jig 1 according to the present embodiment described above, the prestressing steel material P1 can be lifted while being fixed at an arbitrary position such as the end portion or central portion in the longitudinal direction. Therefore, not only is the usability improved when lifting with a crane or other lifting machine, but also the problem of a longer lifting distance can be solved.

In addition, this eliminates the need for a large hoist, and solves the problems of increased cost of the hoist, the problem of carrying the hoist to the construction site, and the problem of the installation space for the hoist.

Furthermore, according to the PC steel material lifting jig 1, since the hanging plate 3 having the hanging hole 31 is attached, the PC steel material lifting jig 1 can be hung on the hook of the lifting machine using a shackle or the like. is easy.

In the above, the PC steel material lifting jig according to the embodiment of the present invention has been described in detail. However, the above-described or illustrated embodiments are merely illustrative of specific embodiments for carrying out the present invention. Therefore, the technical scope of the present invention should not be construed to be limited by these. In particular, the diameters and dimensions of the members of the PC steel material lifting jig illustrated as an embodiment are merely examples, and needless to say, the design can be appropriately changed according to the diameter of the PC steel material.

1: PC steel lifting jig 2: jig main body 20: main body plate 21: notch hole 21a: wedge contact portion 21b: notch portion 22: bolt hole 23: overtightening prevention bolt 24: female screw portion 3: lifting For plate 30: Plate main body 31: Suspension hole 4: Wedge 5: Holding plate 50: Plate main body 51: Notch 52: Bolt hole 6: Bolt P1: PC steel material

Claims (2)

A PC steel material lifting jig for fixing and hooking a PC steel material to a hook of a lifting machine for lifting,
A jig body having a tapered notch hole corresponding to the outer shape of the wedge and decreasing in diameter downward, and a pressing plate for pressing and fixing the wedge to the jig body,
the holding plate and the jig body are detachably bolted together,
A prestressing steel material lifting jig, wherein the jig body is formed with a female threaded portion for mounting an over-tightening prevention bolt. The prestressing steel material lifting jig according to claim 1, wherein a hanging plate having a hanging hole is attached to an end portion of the jig body.

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