JPH0477097B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for embedding an embedding fitting with a nut for attaching an ALC board to a structure frame into an ALC board base material.

The ALC board, an autoclave-cured lightweight aerated concrete board, has embedded fittings with nuts for attaching the board to the building frame. Generally, these embedded metal fittings are fixed to reinforcing reinforcing bars and placed in place prior to manufacturing the ALC board, and mortar is injected into them, so if left as is, the mortar will seep into the nut screw holes and clog them. For this reason, in the past, a bolt was screwed into the nut screw hole to close it off, but in this method, after forming and curing, the nut is manually dug out using a chisel or the like near the embedded position of the embedded metal fitting, and then the nut is inserted. You must remove the bolt that is located on the outside and open the nut screw hole to the outside.

In other words, in the past, the accuracy of the embedded position of the embedded metal fittings had a tolerance of about ±5 mm, and there was no practical sensor to detect when the embedded metal fittings were close to each other, and the process of removing the bolt by rotating it was difficult. Therefore, it was not possible to mechanize the opening of the nut of the embedded metal fitting, and the opening of the nut depended on manual labor.

This invention was made in view of the above circumstances, and its purpose is to propose a method for embedding an embedded fitting that facilitates the opening of the screw hole of the nut of the embedded fitting and that can be mechanized and improve work efficiency. be.

The gist of this invention is to arrange reinforcing bars, inject mortar slurry, and autoclave curing.
In manufacturing the ALC board, an embedded metal fitting with a nut is fixed and integrated with the reinforcing bar, and a filler that melts at the temperature during autoclave curing to reduce the volume is placed in the nut hole of the embedded metal fitting. An embedded metal fitting characterized in that its tip protrudes a predetermined length from the opening end of a screw hole, and is inserted so that the diameter of the protruding portion is equal to or less than the outer diameter of the nut, and then mortar slurry is injected and buried. It's in the burial method.

Embodiments of the present invention will be described below with reference to the drawings.

Figures 1 and 2 show an embedded metal fitting, which consists of a plate 1 made of a steel plate and a nut 2 fixed to its surface, with two parallel protrusions 3, 3 protruding in a V-shape on the back side. There is. Before embedding this embedding fitting in the ALC board, screw hole 4 of nut 2 in advance.
A cylindrical filler 5 is inserted into the hole to close it, and one end thereof is made to protrude a predetermined length from the open end of the screw hole.

The filling material is made of polyethylene foam, ALC
It melts and reduces its volume at the autoclave curing temperature of the plate. In addition, it is flexible and can be tightly inserted into screw holes, preventing mortar from entering.

As shown in Fig. 3, the embedded metal fitting with the screw hole closed with the filler is fixed by spot welding to the reinforcing reinforcing bar 6 at the apex position of the protrusion 3 on the back surface of the plate 1.
After integrally arranging reinforcement, mortar slurry is injected and it is buried in the ALC board 7. At this time, the mortar slurry does not enter the nut screw hole 4.
Further, by curing in an autoclave, the filler 5 is thermally melted to become a solidified resin 8 and its volume is reduced. Therefore, after autoclave curing, a gap 9 is formed outside the screw hole 4 of the nut 2 of the embedded fitting and its open end.

In this method, the length of the protrusion of the filler 5 is set to be 10 mm or more from the end of the nut 2, and a gap 9 close to this length can be formed. Therefore, even if there is a slight error in the accuracy of the nut installation position, the tip position of the counter-boring cutter can be set within the gap 9, and the mechanized cutter can be used to absorb the setting error of the embedded metal without fear of contacting the nut. Vertical movement allows for seat digging.

The diameter of the protruding portion of the filler 5 is equal to or smaller than the outer diameter of the nut. Moreover, the shape is not limited to a cylindrical shape.
For example, as shown in FIG. 4, a filling material 5 having a T-shaped cross section and consisting of a concentric small diameter part and a large diameter part may be inserted, with the small diameter part inserted into the screw hole 4 and the large diameter part 5a protruding. When this filler 5 is inserted, it is embedded in the ALC plate 7, and after curing in an autoclave, a gap 9 having an outer diameter approximately equal to the outer diameter of the nut 2 can be formed at the tip of the nut 2, as shown in FIG.

FIG. 6 shows a state in which a notch 11 is formed by counter-boring with a rotary desk-shaped counter-boring cutter 10, and a nut screw hole 4 is opened. At this time, if the diameter of the cutter is made large, it is possible to communicate with the cavity 9 even if the positional accuracy of the embedded metal fitting is somewhat poor.

The filler inserted into the nut screw hole must be one that melts and reduces its volume at the autoclave curing temperature of the ALC board. In other words, it is a material such as polyethylene or polystyrene that melts at a temperature of around 150℃, which is the temperature of the ALC board base material during autoclave curing, and a foam that decreases in volume by melting.
A hollow shell or the like is suitable for this purpose. The filler must fit into the screw hole to close it, and one end of the filler must protrude a predetermined length from the open end of the screw hole. If the protrusion length is short, the gap formed on the outside of the screw hole will be small, and when opening the screw hole to the outside, the gap between the cutter and the nut will become narrow, which is not preferable since there is a risk of contact. Furthermore, if the protruding length is too long, there is a possibility that the filler material will come into contact with a cutting tool such as piano wire when manufacturing a plurality of ALC plates by slicing them to a predetermined thickness using piano wire or the like, which is not preferable. The protrusion length is selected from a range of approximately 5 mm to 20 mm.

This invention is as described above, and according to this embedding method, the embedding metal fittings buried in the ALC board obtained by autoclaving create a gap in the nut screw hole and the periphery of its tip, so there is some error in the embedding position accuracy of the metal fitting. Even if there is a problem, the error can be absorbed by the gap, and the nut screw hole can be opened by mechanized counter-boring, improving work efficiency. Furthermore, since the gap formed at the tip of the nut after autoclave curing has a diameter that is approximately equal to or smaller than the outer diameter of the nut, unnecessarily large voids will not occur.

[Brief explanation of the drawing]

Figures 1 and 2 are a perspective view and a vertical sectional view of an embedded fitting in which the filler of the example is inserted into a nut screw hole;
Figure 3 is a longitudinal cross-sectional view of an ALC board obtained by embedding the embedded metal fittings and curing them in an autoclave. Figures 4 and 5 are the embedded metal fittings and the embedded metal fittings in which the filler of another example was inserted into the nut screw hole. Longitudinal cross-sectional view of the ALC board with embedded
FIG. 6 is a vertical cross-sectional view of a rotary disk-shaped counter-boring cutter and an ALC plate used for counter-boring. 1...Plate, 2...Natsu, 3...Protrusion,
4...Screw hole, 5...Filling material, 6...Reinforcement reinforcing bar,
7...ALC board, 8...solidified resin, 9...void,
10...Knife for spot digging, 11...Notch, 5a...
Large diameter part.

Claims (1)

[Claims] 1. When manufacturing the ALC board by arranging reinforcing bars, injecting mortar slurry, and curing in an autoclave, the embedded metal fittings with nuts are fixed to the reinforcing bars and integrated, and the nuts of the embedded metal fittings are A filling material that melts and decreases in volume at the temperature during autoclave curing is inserted into the hole so that its tip protrudes a predetermined length from the open end of the screw hole, and the diameter of the protruding portion is equal to or less than the outer diameter of the nut, A method for burying an embedded metal fitting, which comprises subsequently injecting mortar slurry and burying the metal fitting.